Al-Mg-Ga牺牲阳极的电化学性能研究

摘要

目的 研究Al-Mg-Ga牺牲阳极的电化学性能及其与标准铝合金牺牲阳极复合后的性能.方法 设计一种Al-Mg-Ga铝合金牺牲阳极,通过4天加速试验和模拟实海实验研究其电化学性能、初始极化性能以及与Al-Zn-In-Si基底阳极不同面积比复合后的耦合电位.对腐蚀不同状况下的铝活性阳极进行能谱分析(EDX)和扫描电镜(SEM),探讨其活化机理.结果 4天加速试验显示,Al-Mg0.6%-Ga0.05%牺牲阳极开路电位、工作电位较负,分别达到-1.5 V(vs. SCE)和-1.3 V(vs. SCE),适合作为复合阳极中的活性阳极材料.模拟实海试验显示,铝铝复合阳极在阴极保护中初始极化性能良好,能够发出较大电流,得到了-1.2~ -1.3 V (vs. SCE)之间的耦合电位.结论 研制的铝铝复合牺牲阳极发出的初始电流约为中期电流的3倍以上,同时不同的面积比设计的复合阳极耦合电位在-1.2~ -1.3 V(vs. SCE)之间.%Objective To research electrochemical performance of Al-Mg-Ga sacrificial anode and the proper ties of the composite anode, which were combined with the standand aluminium alloy sacrificial anode. Methods An Al-Mg-Ga aluminium alloy sacrificial anode was designed to study electrochemical property, initial polarization property and cou-pling potential with Al-Zn-In matrix anode at different area ratio by 4-day acceleration test and simulation field test. SEM and EDX analysis were used to discuss the excitation mechanism. Results The open circuit potential and working poten-tial of Al-Mg0.6%-Ga0.05% sacrificial anode were more negative, reaching -1.5 V (vs. SCE) and -1.3 V (vs. SCE) re-spectively. It was suitable to be used as active anode in composite anode. The simulation field test showed that the initial polarization property of Al-Al composite anode was good in cathodic protection. It could put large current to get the cou-pling potential between -1.2 to -1.3 V (vs. SCE). Conclusion The initial current sent by Al-Al composite anode devel-oped is 3 times more than that of the middle current, at the same time, the area ratio of different design of composite an-ode coupled potential is 1.2 - 1.3 V (vs. SCE).